EXCLUSIVE: Paul Walker's Brothers Open Up About How Shooting 'Furious 7' Helped Them Grieve and Future Plans f

After Paul Walker's untimely death in November 2013, the star's brothers, Cody and Caleb, stepped up to help complete the production of Paul's final film, Furious 7. Now, nearly three years later, the dedicated siblings are still working hard to honor their brother's memory and legacy.

Caleb and Cody recently sat down with ET's Cameron Mathison to promote the second annual Game4Paul fundraiser benefiting the late star's disaster relief nonprofit organization, Reach Out WorldWide, and they opened up about their experiences on the set of Furious 7.

According to the pair, filming the action flick in their brother's place "absolutely" helped them grieve and come to terms with the painful loss.

"We got to understand more about Paul, and what he was all about," Caleb shared. "We had to share Paul with a lot of people, in a weird way. He was gone a lot, he was filming, so we missed him. Sometimes at the holidays he wasn't always there, you know? He tried. We'd see him on set, we visited a few times, but to kind of get that closure, and understanding [of] Paul was really special."

Working with Paul's close friends in the cast, Caleb said that the brothers learned more than they expected about their famous sibling, and heard "some really cool stories about him" that they never knew.

"We had a really good talk with Vin [Diesel]. Vin is like the godfather, he really is, and he kind of became our godfather in a weird way," Caleb recounted. "He obviously knew Paul so well, he shared things with us that Cody and I [didn't know.]"

"Paul kept a lot of things about work kind of quiet with his family and friends, and so we were able to learn some things through [his co-stars]," he added.

While Furious 7 paid farewell to Paul's character, Brian O'Conner, in an emotional parting of the ways, it seems that discussions have taken place regarding O'Conner making a brief cameo in the franchise in the future, with the help of Caleb and Cody.

"I had a phone call with Vin for about an hour and we really discussed this a while back. He wanted [our] blessing," Caleb said, adding that Diesel asked if and when they thought it "would be acceptable to maybe bring Paul's character back… to really kind of let his fans know he's still out there."

"Universal wants to make sure to be respectful of Paul and his image too, and his family," Cody added.

When Walker died, he left behind his young daughter, Meadow, who will be turning 18 this November. According to Cody, Meadow is "doing a lot better" since the accident.

"She was the most important thing in the world to him," Cody said. "So we're very protective of her."

The two are also very dedicated to making sure Paul's passion project, Reach Out WorldWide, continues to thrive. Today, ROWW is in Louisiana helping the victims of the recent flooding that has devastated the state.

"It's what he left behind for us, and for that reason we're going to support it and keep it going for as long as we possibly can," said Cody, who has taken over running the charity with his wife, Felicia. "It's a piece of him."